Customising jQuery UI Dialog Footer/button bar

I have a very simple and quick question that 开发者_如何学GoI cannot find the solution for after about an hour of Googling.

I have a jQuery UI dialog that has a list of rows in a table. They represent entries in a database, and are selectable (checkboxes).

In the bottom bar of the dialog, I want to add a couple of custom items in - NOT the buttons that the documentation mention, but instead a dropdown box so users can select where they want selected entries moved to, and then click a button to submit the form.

How can I customise the content in the dialog footer/button bar?